The agrarianism will deposit calcium carbonate, and as the crack fill up, the supply of oxygen and carbon dioxide will be interrupted, causing the microorganisms to hibernate again, ensuring the continual effectiveness of the microorganisms in filling up cracks at the same location. Mondale said there are a few ongoing research projects in several parts of the world on the use of microorganisms in developing self-healing construction materials, and researchers are reporting that the familiarization technique is promising based on its effect on compressive strength due to filling up pores inside concrete.
However, Mondale said that an increase in compressive strength is not sufficient proof that the bond between the newly developed deposit and the cracked material is sufficient to regain part of the strength lost due to cracking. "That is the specific goal of our project," she said. "We are testing the specimen to see whether the crack is going through the filling material, through the original material, or through the interface. That will tell us which part is the weakest.
" "Conceptually, all of this should work," Mondale concluded, "but there is lots more research to be done.It's an innovative concept?definitely outside the box. Bendable Concrete Heals Itself Just Add Water Anne Marina for National Geographic News May 5, 2009 Its not quite as advanced as Terminator technology. But a new concrete that can heal its own wounds may soon bring futuristic protection to bridges and roads. Traditional concrete is brittle and is easily fractured during an earthquake or by overuse.
"Lunar Concrete" May Form Buildings on the Moon Self-Healing Coating May Erase Gadget Scratches By contrast, the new concrete composite can bend into a U-shape without breaking.When strained, the material forms hairline cracks, which auto-seal after a few days of eight rain. Dry material exposed by the cracks reacts with rainwater and carbon dioxide in the air to form "scars" of calcium carbonate, a strong compound found naturally in seashells, said study co-author Victor Lie of the University of Michigan in Ann Arbor. The flexible material is Just as strong after it heals, the study authors report.
Quiet Concrete For the past 1 5 years L', along with colleagues such as study leader and visiting scholar Wing Yang, has been developing next-generation concrete for various applications.Similar self-healing concrete has already been used inside the core of Osaka, Japan's alleles residential building, a 60-story structure, Lie noted. The material was also used in a bridge built in 2006 over Interstate 94 in Michigan, where it eliminated the need for traditional expansion Joints. These "toothed" metal slats allow normal concrete to expand and contract without bending, but they can create significant road noise as vehicles rattle over them.
"One of the big attractions, apart from reducing maintenance requirements, is the fact that [the new concrete] is very quiet" without expansion Joints, Lie said.Self-healing concrete is now being considered for use in irrigation channels in Montana. Although it costs three times as much as traditional concrete, the material is a cost- saver in the long run, due to its reduced maintenance needs and energy demands, Lie said. Builders using the bendable concrete, for example, don't need to buy and install devices that counter seismic activity.
"The initial building cost actually becomes lower," Lie said. Hajj, two engineers who devised a clever way for a building to collapse in on itself? but not fall over?during the rumblings of a major earthquake.To test it out, Dernier and Hajj took their system to Mike City, Japan, where the world's largest earthquake simulator resides. But today, what Japan felt was no simulation?a huge 8. 9 earthquake hammered the island country and launched tsunamis that destroyed buildings on the Japanese coast and killed people in the hundreds at least. Unfortunately, Hajj tells PM today, his and other disaster-proofing technologies are so new that they're still in testing or in very few buildings.
But soon, he says, Japan? boasting its traditions of smart building and preparedness that might have saved many lives today?could begin widespread use of these new technologies that to help structures withstand even these largest natural disasters. "There are some regressive practitioners both in the United States and Japan who have been trying out variations on this simultaneously with us," he says. In Japan, Hajj says, researchers are working on two or three systems that share a lot with his Breakthrough Award-winning design. They've been exploring this not only for engineered structures, but also non-engineered structures?meaning houses. " For example, he says, Japanese industrial giant Nippon Steel is researching fuses that resemble what he uses?structural connectors that absorb the stress of an earthquake. "They use those to connect different pieces of wood frame construction, n order to focus any damage in those structures into those fuses.
" In fact, Hajj says, Nippon recently displayed those fuses in its showroom in Chief, Japan, "one of the places that got a pretty hard shake today. He emailed the folks at Nippon this morning to see how they were doing, but hadn't heard back when he spoke with PM. Because of its precarious location in an earthquake-prone zone, Japan has absorbed disaster readiness into its culture, Hajj says?and into its building codes. "They're shaking almost daily," University of California, Davis engineering professor Boris Ceramic says. So they not only need good codes, they need good enforcement.
" Japan has that, he says. But while the country has been proactive in its safety demands for new buildings, retrofitting older ones is another matter.Like American private homes, Hajj says, when Japanese buildings aren't required to be retrofitted they suffer the same kind of disaster vulnerability. However, Hajj says, while earthquake-resistant designs show plenty of promise, there's not a lot you can do to stave off the rage of flooding water.
There's a tiny community of researchers in the U. S. And around the world who are trying to make alluding tsunami-resistant, he says, but those the scientists have come up with some solid ideas.Honolulu, Hawaii, for instance, has experimented with designs that include a "sacrificial first floor," in which water will run right through it without some Hawaiian buildings enacted vertical evacuation?meaning the occupants went upward in the building to avoid the floodwater's in the bottom.
Tsunami scientists at Oregon State University are also moving on up: They plan to build a test structure standing on pillars in Cannon Beach, Ore. , which would become both the town's city all and an elevated refuge from tsunami waters.
